Lost in Thoughts All Alone (if～ひとり思う～ if ~hitori omou~ lit. if ~one's thoughts~) is Azura's song in Fire Emblem Fates and the main theme of the game. The Japanese version is sung by Renka, while the English version is sung by Rena Strober.
The Japanese version of the song received an album release shortly after the release of Fates itself, and also received a limited edition release. The album contains two versions of Lost in Thoughts All Alone itself as well as two other songs by Renka, and the limited edition adds a DVD with two music videos for Lost in Thoughts All Alone, one of which is Fire Emblem-themed.
Lost in Thoughts All Alone is a special song that anyone can sing. However, the song has magical properties when it is sung by a member of Vallite Royalty and the singer is wearing a special pendant. The song, at its weakest power, can rejuvenate allies so they can perform another turn of action. With more effort put into the song, it can dispel possessions, release traps, and quell a raging dragon. It is only known by Azura and was taught to her by her mother.
The song, while powerful in its effects, is not without drawbacks. The usage of the song requires a great deal of energy and constant usage can lead to great pain to the singer. Overuse of the song in a short period of time can result in the death of the singer, causing them to liquify and dissipate into mist.
The original version of the song first sung in the first trailer for Fates is sung during the Birthright route. She sings a much faster, different tempo, and lower key version of the song during Conquest. Her dance during the different versions of the song are also different. Her Hoshido route dance is slower and graceful while her Nohr dance is faster and passionate.
In Mokushu, a possessed Takumi ambushes the Avatar's army as they try to rescue Kagero. Azura notices him and sings the song, dispelling the mysterious possession over him.
As the Hoshidan army begins their invasion of Nohr, word reaches the army of King Garon attending a performance at the Opera House. Seeing the opportunity to kidnap the king and end the war, Zola is forced to use his disguise magic to make Azura appear as Layla. In the Opera House, she sings the song, causing strong discomfort to King Garon. However, the attempted kidnapping results in failure, forcing the Hoshidan army to flee. As they flee, the Avatar notices a purple haze appearing over Azura's shoulder. She tells the Avatar not to worry.
In Chapter 20, the Hoshidan army is trapped in Fort Dragonfall and Azura uses the song to allow the army to escape. Azura isolates herself to a nearby lake where she is slowly being consumed by a purplish miasma surrounding her body. It dissipates shortly after, but Azura is left severely exhausted. Azura explains the reason for the purple miasma, telling them that using the song causes it and that if she continues to use it in the same magnitude, she may die. The Avatar makes her vow to not use it as much as possible.
In the Endgame, King Garon transforms into a dragon, forcing Azura to sing the song in order to weaken him enough so he can be slain. After Garon is finally killed, Azura's body quickly liquifies and she disappears.
In Chapter 14, the Nohrian army is invited to Cyrkensia to watch an opera performance at the Opera House alongside King Garon. During the performance, Azura slips away and dons a dark purple version of her dress with a veil and sings a slightly different version of the song. The song causes great discomfort in King Garon, causing his eyes to roll back. Seeing this, a man hunt begins for the mysterious singer, though none are able to "find her".
After the massacre at Cyrkensia, the Avatar catches Azura singing the song at a lake, opening a portal to Valla.
The Avatar and Azura discuss its possible origins: while the true origin was lost in time by that point, Azura speculates that it acted as a cry for help from Anankos for those who understood the meaning of the lyrics and to free him from his madness with death.
In the Record Hall's ancient texts, the three separate verses of the song are listed as the prophecies of Sky, Land and Below and are said to be the three prophetic songs meant to save Anankos when he descends into madness. The Prophecy of Sky contains the Birthright verse, and the verse appears in the End of All (Sky). The Prophecies of Land and Below also correspond to End of All (Land) and End of All (Below) respectively. The Sky version is sung in the Birthright Endgame, the land version is sung in the Conquest Endgame, and the Below version is sung in the Revelation Endgame.
The song's origin is finally revealed in Hidden Truths, where Anankos reveals himself as its the creator. It was meant to be used by a Songstress in conjunction with the pendant made from a piece of his Dragonstone to weaken himself. However, it began to lose its effect on him over time and the use of the pendant started killing the Songstresses. The song itself is meant to be sung from Anankos' perspective about his child, the Avatar. If the song is sung without the pendant, it has no effect aside from being a normal song.
In Heirs of Fate, it is revealed there is a fourth verse of the song that is too powerful for even Azura to sing, which both the first King of Valla and Shigure can at the cost of vanishing. Azura teaches Shigure the verse to save the world where they failed to defeat Anankos after going to Valla.
Azura's son Shigure also learned to sing the song and often sang it with Azura as he grew up. In his supports with Azura, he has trouble hitting the right notes due to his voice changing. At the end of his Paralogue, Shigure sings the song as a requiem for his fallen caretakers who gave up their lives protecting him from invisible forces that invaded his Deeprealm.